INORGANIC EVOLUTION. 



19 



and that they differ in properties and in size simply as they 

 contain a greater or smaller number of these corpuscles ; all the 

 corpuscles being exactly similar to each other in every respect 

 from whatever source they may be derived. So that we have in 

 reality only one and the same kind of primordial matter 

 underlying and making up all the different substances which 

 are in existence. An atom may therefore be looked upon as 

 a body more or less spherical in form, of exceeding minuteness, 

 constantly oscillating to and fro at a very rapid rate, and 

 containing within it a very large number of inconceivably small 

 bodies called corpuscles. The hydrogen atom, the lightest 

 known, contains at least 1,000 corpuscles, while an atom of 

 radium is composed of at least 224,000. The corpuscles are 

 continually moving backwards and forwards within the atom 

 with inconceivable rapidity, their rate of motion being at least 

 10,000 miles per second. These corpuscles are probably 

 indivisible specks of matter. They are now known to exist 

 under certain conditions in a free state. The flame of a candle, 

 for instance, has been found to give off certain minute bodies 

 called ions. These ions are of two kinds, charged respectively 

 with positive and with negative electricity. The former, which 

 are given off in greater quantity at a lower temperature and 

 under greater pressure, are considered to be free atoms, that is, 

 atoms not combined with other atoms to form molecules, as is 

 the case in ordinary forms of matter whether compound or 

 elementary. The latter, charged with negative electricity, and 

 given oif in greater quantity at a higher temperature and under 

 lower pressure, are the corpuscles we are talking of. These 

 corpuscles are also given off from highly heated metals and 

 from glowing carbon. They travel with a velocity of from 

 10,000 to 90,000 miles per second. They are formed also in 

 connection with electrical discharges. They constitute the so- 

 called beta rays, which are continually being given off by the 

 metal radium as well as by uranium, thorimn, and some other 

 rare metals with high atomic weights. Those corpuscles do not 

 remain free, but almost immediately unite with each other to 

 form new atoms and molecules, in some cases forming molecules 

 of elementary bodies which differ in character from the elements 

 from which they (the corpuscles) have proceeded. Thus, the 

 element heliiun has l^een shown to be derived from and to be 

 what we may call a decomposition product of radium. Truly 

 the old Alchemists, who have been held up to derision and scorn 

 for hundreds of years, were not so very far wrong after all when 



